Cities may be the defining element of human civilization.
The path from hunter-gatherers in the Paleolithic era 25,000 years ago to the high-tech, high-wonder jumble we inhabit today runs straight through cities. In traveling that path, our construction of cities has always been a dance with physics. In some cases, that physics was explicitly understood; in others, its manifestation was only recognized in hindsight.
As our cities have become more complex the physics embodying their behavior and organization has also become more nuanced, subtle and profound.